The invention relates to battery chargers, and more particularly, to battery chargers including means for controlling the charging rate of a battery in response to electrolyte gassing in the battery.
Heretofore, some battery chargers have operated by sensing the voltage at the battery terminals. Full charging occurred until a predetermined battery terminal voltage was sensed, and then the charger would turn off or switch to a trickle charge state. In some battery charger arrangements, after the predetermined battery terminal voltage was sensed, a timer would be activated to continue full charging for a predetermined period of time and then switch to a trickle charge state. Several variables affect battery terminal voltage, and thus the battery charging process, for example, battery age and temperature, the battery state of charge, line voltage, and battery discharge history from the charging process. These variables make satisfactory battery charging based upon sensing battery terminal voltage difficult to achieve.
Prior battery chargers, including chargers which are regulated by sensing gas pressure in the battery, are disclosed in the following U.S. Pat. Nos.:
Mas 3,460,019 issued Aug. 5, 1969 PA0 Mas 3,281,640 issued Oct. 25, 1966 PA0 Molyneux 3,798,728 issued Mar. 19, 1974 PA0 Sulger 3,781,751 issued Dec. 25, 1973